import java.util.Scanner;

public class Time_2 {
    public static void main(String[] args) {
        Scanner input=new Scanner(System.in);
        double sum=0;
        for (int i=1;i<=5;i++){
            System.out.println("请输入周"+i+"的学习时间");
            int time=input.nextInt();
            sum+=time;
        }
        double average=sum/5;
        System.out.println("平均数："+average);
    }
}
